1. Field of the Invention
This invention relates generally to text processing systems and, more particularly, to a system control and storage method for interactively prompting an operator with the synonyms or antonyms of a word during document preparation or revision.
2. Description of the Prior Art
In implementing office systems and their expansion to principal support terminals, the cost displaceable benefits of such systems are highly dependent on automating functions that would normally be done manually and repetitively during document composition or editing. Examples of such functions, that can now be performed for the operator by virtue of the computer facilities in an office system, are automatic hyphenation, spelling verification and spelling correction. These functions enable the operator to enter text more reliably and to find misspelling or typographical errors in the text. A logical extension to the automated text processing technology to aid the operator or principal in composing a document is an automatic thesaurus. Such a function would prompt the operator with alternate ways of expressing a word or idea, e.g. synonyms. This requires storing on-line the information content of a thesaurus type dictionary.
Procedures have been developed in the prior art to perform some aspects of a synonym generation function. The simplest approach amounts to storing word for word the contents of a synonym dictionary. The information and synonymy are then accessed by the key words of the dictionary or thesaurus index. This synonymic data base approach leads to a high degree of redundancy, massive storage requirements, and no ability to cross reference between synonym entries or to access any other words in the data base except those that have been chosen as the set of index terms.
Another method for automatic synonym generation provides a linked data base. This requires that every word in the data base have a pointer to the next word to which it is related. Similarly, a word may have several pointers to other words to create an inverted data base. In theory, the linked data base can be entered at any word, and followed through to all of the words that bear a synonymic relationship to that word. The penalty paid for this flexibility is the enormous amount of storage required for the pointers that allow cross referencing within the data base. Implementation of an antonym dictionary requires a totally separate vocabulary data base with the link entries rearranged to provide antonymy. Because of the voluminous data involved in such a data base, and the many cross references involved in synonymy, such a function has not heretofore been practical within the price and performance requirements for text processing systems.